Consolidated Statements of Comprehensive Income - USD ($) shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
OPERATING REVENUE
Rental	$ 139,143,000	$ 147,367,000	$ 278,198,000	$ 295,952,000
Operating expense reimbursement	47,511,000	56,151,000	98,597,000	114,467,000
Total operating revenue	186,654,000	203,518,000	376,795,000	410,419,000
OPERATING EXPENSE
Rental property	24,745,000	31,949,000	53,255,000	67,520,000
Real estate taxes	25,202,000	26,462,000	50,522,000	52,626,000
General and administrative	15,629,000	17,053,000	36,619,000	35,855,000
Depreciation and amortization	53,545,000	56,833,000	107,623,000	115,629,000
Impairment - real estate assets	0	1,036,000	0	16,775,000
Total operating expenses	119,121,000	133,333,000	248,019,000	288,405,000
Operating income	67,533,000	70,185,000	128,776,000	122,014,000
OTHER INCOME (EXPENSE)
Interest and other income	4,992,000	6,581,000	9,590,000	12,952,000
Interest expense	(30,131,000)	(35,066,000)	(61,543,000)	(69,736,000)
Total other income (expense)	(25,139,000)	(28,485,000)	(51,953,000)	(56,784,000)
Income before gain on property dispositions, income taxes and equity in earnings (loss) of unconsolidated joint ventures	42,394,000	41,700,000	76,823,000	65,230,000
Gain on property dispositions	3,832,000	1,249,000	24,353,000	3,520,000
Income taxes	(752,000)	(1,169,000)	(1,553,000)	(2,014,000)
Equity in earnings (loss) of unconsolidated joint ventures	5,583,000	(5,254,000)	10,497,000	1,652,000
Income from continuing operations	51,057,000	36,526,000	110,120,000	68,388,000
Net income	51,057,000	36,526,000	110,120,000	68,388,000
Noncontrolling interest – operating partnership	(1,317,000)	(958,000)	(2,826,000)	(1,811,000)
Noncontrolling interest - consolidated joint ventures	(113,000)	(55,000)	(113,000)	(113,000)
Net income available to common shareholders	49,627,000	35,513,000	107,181,000	66,464,000
Comprehensive income attributable to common shareholders
Net income	51,057,000	36,526,000	110,120,000	68,388,000
Other comprehensive (loss) gain - foreign currency translation	(13,509,000)	12,151,000	(18,596,000)	1,741,000
Other comprehensive (loss) gain - derivative instruments	(435,000)	628,000	(1,795,000)	(319,000)
Other comprehensive (loss) gain	(13,944,000)	12,779,000	(20,391,000)	1,422,000
Total comprehensive income	37,113,000	49,305,000	89,729,000	69,810,000
Less: comprehensive income attributable to noncontrolling interest	(1,101,000)	(1,309,000)	(2,458,000)	(1,957,000)
Comprehensive income attributable to common shareholders	$ 36,012,000	$ 47,996,000	$ 87,271,000	$ 67,853,000
Weighted average number of common shares outstanding
Basic	145,995	148,778	146,002	148,574
Diluted	146,735	149,454	146,622	149,247
Amounts attributable to common shareholders
Net income available to common shareholders	$ 49,627,000	$ 35,513,000	$ 107,181,000	$ 66,464,000
Liberty Property Limited Partnership [Member]
OPERATING REVENUE
Rental	139,143,000	147,367,000	278,198,000	295,952,000
Operating expense reimbursement	47,511,000	56,151,000	98,597,000	114,467,000
Total operating revenue	186,654,000	203,518,000	376,795,000	410,419,000
OPERATING EXPENSE
Rental property	24,745,000	31,949,000	53,255,000	67,520,000
Real estate taxes	25,202,000	26,462,000	50,522,000	52,626,000
General and administrative	15,629,000	17,053,000	36,619,000	35,855,000
Depreciation and amortization	53,545,000	56,833,000	107,623,000	115,629,000
Impairment - real estate assets	0	1,036,000	0	16,775,000
Total operating expenses	119,121,000	133,333,000	248,019,000	288,405,000
Operating income	67,533,000	70,185,000	128,776,000	122,014,000
OTHER INCOME (EXPENSE)
Interest and other income	4,992,000	6,581,000	9,590,000	12,952,000
Interest expense	(30,131,000)	(35,066,000)	(61,543,000)	(69,736,000)
Total other income (expense)	(25,139,000)	(28,485,000)	(51,953,000)	(56,784,000)
Income before gain on property dispositions, income taxes and equity in earnings (loss) of unconsolidated joint ventures	42,394,000	41,700,000	76,823,000	65,230,000
Gain on property dispositions	3,832,000	1,249,000	24,353,000	3,520,000
Income taxes	(752,000)	(1,169,000)	(1,553,000)	(2,014,000)
Equity in earnings (loss) of unconsolidated joint ventures	5,583,000	(5,254,000)	10,497,000	1,652,000
Net income	51,057,000	36,526,000	110,120,000	68,388,000
Noncontrolling interest - consolidated joint ventures	(113,000)	(55,000)	(113,000)	(113,000)
Preferred unit distributions	(118,000)	(118,000)	(236,000)	(236,000)
Net income available to common shareholders	50,826,000	36,353,000	109,771,000	68,039,000
Comprehensive income attributable to common shareholders
Net income	51,057,000	36,526,000	110,120,000	68,388,000
Other comprehensive (loss) gain - foreign currency translation	(13,509,000)	12,151,000	(18,596,000)	1,741,000
Other comprehensive (loss) gain - derivative instruments	(435,000)	628,000	(1,795,000)	(319,000)
Other comprehensive (loss) gain	(13,944,000)	12,779,000	(20,391,000)	1,422,000
Total comprehensive income	$ 37,113,000	$ 49,305,000	$ 89,729,000	$ 69,810,000
Weighted average number of common shares outstanding
Basic	149,534	152,317	149,541	152,114
Diluted	150,274	152,993	150,161	152,787
Net income allocated to general partners	$ 49,627,000	$ 35,513,000	$ 107,181,000	$ 66,464,000
Net income allocated to limited partners	1,317,000	958,000	2,826,000	1,811,000
Amounts attributable to common shareholders
Income from continuing operations	50,944,000	36,471,000	110,007,000	68,275,000
Net income available to common shareholders	$ 50,826,000	$ 36,353,000	$ 109,771,000	$ 68,039,000
Common shares [Member]
Basic:
Income per common share - basic	$ 0.34	$ 0.24	$ 0.73	$ 0.45
Diluted:
Income per common share - diluted	0.34	0.24	0.73	0.45
Distributions per common share or unit	0.475	0.475	0.95	0.95
Common Units [Member] | Liberty Property Limited Partnership [Member]
Basic:
Income per common share - basic	0.34	0.24	0.73	0.45
Diluted:
Income per common share - diluted	0.34	0.24	0.73	0.45
Distributions per common share or unit	$ 0.475	$ 0.475	$ 0.95	$ 0.95